1. Field of the Invention
This invention relates to a connector set that joins a gas column catheter to a pressure transducer airway in a manner that injects air into the catheter's bladder. The connectors ensure that the catheter is operable for no more than a single use.
2. Description of the Prior Art
Air column catheters have certain attributes that make them especially useful in measuring pressure in the body including natural body passageways such as the urethra or esophagus. These catheters may have a single bladder or a plurality of bladders, each of which is in communication with a dedicated pressure transducer. The bladder of an air column catheter can function for extended periods. It is therefore possible to use a gas column pressure-monitoring catheter in more than one patient. Reuse is not advisable, however, since a bladder will eventually fail and may do so in a manner that affects the accuracy of the pressure reading and the proper treatment of the patient. Consequently, there is a need to limit the use of an air-based catheter to a single patient.
There is little incentive to reuse most air column catheters that measure pressure in the body. Either the risk of infection is too great to justify reuse or the catheter has structural elements that make cleaning and resterilization quite difficult. Concern for infection is much less in the case of catheters introduced through natural body orifices such as the esophagus or the urethra. There is an economic incentive to reuse the catheter even though the manufacturer specifies that it is designed for single use. Reuse can lead to an uncontrolled situation where there is no awareness of the number of times the catheter has been reused. At some point, the bladder will leak and the catheter will no longer function properly. Since the leak may be small, it may not be obvious that the catheter is incapable of correctly reading pressure. If the observed pressure is incorrect, the patient may be mistreated based on invalid pressure values. The risk of bladder failure is proportional to the number of bladders on the catheter. For example, a urethra catheter may have two bladders on a measuring catheter and one on a separate reference catheter. A esophageal catheter may have four to six bladders.
U.S. Pat. No. 5,573,007 (Bobo) describes a connector and transducer housing that, when coupled, automatically injects air into a bladder of an air column catheter so as to make it operative.